This invention relates to devices with an electric motor for rotationally driving a multi-bladed fan.
Electric motor driven fans are well known in the art. Examples of such devices are illustrated in U.S. Pat. No. 2,472,039 issued May 31, 1949 and U.S. Pat. No. 2,628,771 issued Feb. 17, 1953, the disclosures of which are hereby incorporated by reference. FIG. 1 is a side perspective view illustrating such a device generally designated with reference numeral 10. As seen in this Fig., a multi-bladed fan 11 is mounted on a rotatable shaft 12 driven by an electric motor 14. Motor 14 is supported on a vertically extending pedestal 15, which is secured at the lower end to a base member 17. In some designs, provision is made for enabling motor 14 to rotate in a reciprocating manner on pedestal 15 in order to provide an oscillating motion for fan 11 to distribute the air over an area greater than that covered by a stationary fan.
One difficulty encountered with the device shown in FIG. 1 resides in the fact that the fan motor 14 can be relatively heavy. Since the motor 14 necessarily rests on the top of pedestal 15, the device tends to be top heavy and therefore potentially mechanically unstable. To offset this potential instability, the base member 17 must be relatively large and contain more mass than would ordinarily be required. This results in the device having a relatively larger mass and a much larger footprint, which adversely affects ease of handling and the number of potential locations at which the device may be placed for operational use.